1. Field of the Invention
The present invention relates generally to a snowboard, and more specifically, to a snowboard that is configured to increase downhill speed and stability by decreasing the bottom surface area of the snowboard that is in contact with the surface of the snow and that has increased longitudinal and lateral stiffness.
2. Description of the Art
A typical snowboard is comprised of an elongate, flat board with the forward and rear ends upwardly curved. In most boards, the bottom surface is flat so as to provide maximum contact between the board and the snow surface. Most snowboards are comprised of a layered, laminated structure that is designed to provide rigidity with limited flexibility depending upon the use of the snowboard, whether designed primarily for speed or maneuverability.
A typical snowboard is comprised of a gliding surface having a sole for gliding bordered by metal edges. A lower reinforcing layer, either fibrous or metallic, overlays the sole to which a core is attached. An upper reinforcing layer, either fibrous or metallic, is laminated to the core and covered by a protecting and decoration-supporting foil, made either in the form of a shell and therefore constituting the top and sides of the board, or existing solely on the upper face of the board.
Wood core “cap” construction, a technique which wraps a wooden core in fiberglass and covers the top and sides with a one-piece cap for snappy response, is widespread in the snowboard industry. Certain other designs (e.g., Morrow's 3D Revert freestyle snowboard) have rods which impart progressive flexibility and strength to the snowboard, while others (e.g., Killer Loop's freestyle Trick snowboards) use a modified “fiber tube” cap construction to provide for lighter weight and increased control. Traditionally, however, a laminated wood core construction with no cap has been used.
A core made of wood is relatively heavy, slightly vibrating, and of relatively low cost price. It improves the mechanical characteristics of stiffness, of resistance to deformation and of resistance to tear of the screws maintaining the bindings, as well as the characteristics of adhesion in bonding between the various layers of the snowboard. Compared to a core made of wood, a core made of synthetic foam can be lighter and more dampened, but more expensive. Such synthetic foams include fiber-reinforced polyurethane foam, polyurethane foam and acrylic foam.
It is known to wrap fiberglass (a fiber reinforced composite), around the core to provide a strong and lightweight torsion box construction for a snowboard. A sheet of woven glass (reinforcement) fiber is wetted with a binder resin and wrapped around the base core with a slight overlap, the base core being made of a lightweight wood or a synthetic foam such as polyurethane. The wetted reinforcement fiber sheet is then cured about the base core within a press, wherein heat may be applied for accelerating the curing process. During curing, the press molds the wetted fibers and base core with a desired profile while squeezing out excess resin so that the resulting cured composite is adhered to the base core without air pockets.
A variety of materials such as wood, metal and foam have been used in conjunction with fiberglass in an attempt to achieve a snowboard that is stiffer underfoot and more flexible in the tip and tail to aid in the absorption of bumps and other terrain irregularities. In many snowboards, a layer of plastic, such as P-Tex, is first molded into an appropriate shape for a snowboard. After the layer of plastic has cured, reverse graphics are printed on the plastic layer. Each longitudinal edge of the snowboard is provided with a metal edge that extends the length of the board. The metal edges are adhered to the layer of plastic. The metal edges are typically sharpened to an abrupt 90 degree angle to cut into the snow when turning and thus provide turning ability to the board.
A layer of fiberglass is applied over the surface of the plastic layer. A veneer inset is positioned within the layer of fiberglass. A stiff material such as wood, metal or foam is encapsulated with a fiberglass layer to form a core. Metal plates or inserts are inserted into the core so that bindings may be ultimately fastened to the snowboard. The snowboard is completed by applying a final resin or laminate layer that is applied over the surface of the fiberglass layer and over the edges of the fiberglass layer.
A snowboarder desires various degrees of longitudinal and torsional rigidity depending upon the snowboarding conditions and style. Longitudinal rigidity characterizes the board's ability to bend along its length. Torsional rigidity describes the ability of the board to flex and twist about its longitudinal axis. For downhill speed, a stiff snowboard is generally preferred wherein the longitudinal and torsional flexibilities are limited.
Another snowboard parameter is edging strength, which determines the ability of the board to cut and hold an edge against a slope under forces of a turn or stop. Edging strength is primarily related to the strength of the vertical composite side walls of the torsion box construction formed around the base core. In addition, while carving such a turn or stop, it is common to encounter an object with the edge of the snowboard, which object imparts a localized force to the vertical composite side wall of the torsion box core proximate the point of impact. If great enough, the localized force, which is not uniformly distributed across the snowboard, can cause a fracture in the vertical composite side wall or cause a portion of the board to break away proximate the localized force. Therefore, a strong composite is desired for providing the torsion box core with strong vertical composite side walls. However, in a conventional snowboard, the snowboard's edging strength and rigidity are both related to the strength of the composite of the torsion box core such that increasing the strength of the composite of the torsion box core for improving the board's edging strength in turn decreases the board's flexibility.
Another concern is a strength/weight compromise. In a typical snowboard having a uniform cross-section, increasing board thickness to increased board stiffness proximate the mid-section relative the nose and tail sections will also significantly increase the weight of the snowboard.
One of the problems associated with the metal edges of a snowboard is that a snowboarder can easily and unwillingly perform a maneuver commonly referred to as “catching an edge” in which upon transitioning the board from one edge to the other, the metal edge will quickly engage the snow thus sending the snowboarder to the ground. Especially for beginners, many of their injuries are a result of the board catching an edge and the snowboarder being essentially whipped to the ground. The impact of such whipping often results in broken wrists and other arm injuries.
One snowboard known in the art and referred to as the “tunnelboard” is disclosed in U.S. Pat. No. 6,224,085 to Cruz. The tunnelboard is provided with a profile that defines a longitudinally extending channel along the bottom surface of the snowboard. The cross-sectional thickness of the board, however, is generally uniform in order to maintain the flexibility of the snowboard. The tunnelboard also includes internal edges along the channel to grip the snow. The combination of the flexible board and internal edges results in a snowboard that is unstable at higher speeds and will result in more frequent edge catching as there is significantly more edging of the snowboard due to the internal edges.
Thus, it would be advantageous to provide a snowboard that is generally more torsionally and longitudinally rigid than a conventional snowboard without significant addition of weight to the snowboard. It would be a further advantage to provide a snowboard that is significantly faster than a conventional snowboard of similar size. It would also be an advantage to provide a snowboard that is generally more stable when riding and is less susceptible to edge catching than snowboards known in the art.
These and other advantages will become apparent from a reading of the following summary of the invention and description of the illustrated embodiments in accordance with the principles of the present invention.